The subject invention pertains to improvements in onepiece, molded looseleaf books in which the front and rear cover panels, the optional spine and the parts for removably receiving and holding hole-punched paper sheets, constitute a one-piece molding or two piece moldings of a thermoplastic, synthetic polymer. The most widely used looseleaf book, usually called a looseleaf notebook, uses snap-ring assemblies mounted on the spine of the book, the rings being split and mounted by springable means which allows the split segments of the ring to part in order to add or remove hole-punched paper sheets. Three ring notebooks are well known examples thereof.
Another type of looseleaf book, often used for accounting and financial records, has vertical posts mounted on the rear cover panel or on a strip hingedly connected to said panels, the paper sheets being mounted on the posts. The front cover panel also has a strip hingedly connected thereto, said strip having bolt-holes therein. Bolts are threaded into tapped upper ends of the posts and removably hold the front cover panel on the posts of the book. Removal of the bolts and the front cover panel allows hole-punched paper sheets to be added to or removed from the book.
Book covers made of plastics are known in the art.--U.S. Pat. No. 3,088,753. Book covers with integrally formed plastic hinges are also known in the art.--Defensive Publication No. 535,843, published Dec. 24, 1968; U.S. Pat. No. 3,168,424; U.S. Pat. No. 3,201,145.
None of the prior art known, to applicant, however, has the concept of one piece, molded looseleaf books in which the punched hole paper-mounting posts and the removable member which coacts with the posts are all part of the same one-piece molding as are the front and rear covers and the spine of the looseleaf book; nor the concepts of the two section, molded, looseleaf books hereinafter described.